Glass



I are very valuable for culi Patented Get. 10, I922.

[TED

lhttl ltt cuss.

No Drawing. Application filed September 16, 1316, SerialNo. 120,554. Renewed January 21, 1922.-

' Serial No. 531,004.

To all whom it may concern:

Be it known that I, FRED M. LOGKE, a citizen of the United States of America-and resident of Victor, in the county of Ontario,- in the State of New York, have invented new and useful Improvements in Glass, of which i the following, taken in connection with the accompanying drawings, is a full, clear, and exact description.

This invention relates to certain new and useful improvements in glass and glass manufacture.

Theo-bject of the invention is to produce ,a glass of low coeflicient of expansion and high stability. v

Such qualities are obtained through the combination of silica with boron material, such as boric oxide, and I find that the addition of small amount of an alkali earth such as the metal salts or compounds of barium, strontium, calcium, and magnesium, assists in produclng the stability desired and lowers the melting point of the glass composition, rendering the manufacture more economic. I

The use of the alkalies, such as sodium or potassium,- also lowers the melting point of the lass.

I nd that a glass that is high in silica and boric oxide, combined with small amounts of the metals mentioned or some of the compounds of the metals mentioned, and preferably small amounts of alkalies, has a very low coefiicient of expansion and.

-- the highest stability.

As a specific instance of this invention, I desire to disclose and claim herein a lass of approximately the following analysis:

, analysis is highly efficient for numerous purposes, particularly where a low coefficient of expansion is desired, the s ecific composition disclosed producing a g ass having a coeflicient of expansion of approximately 20000035; Suchgla'sses nary ware, tubing or chemical ware, which is. subject to sud-' den changes of temperature, or to acids or alkalies'.

Further,

A glass of the above by reason of its composition the lass of this invention is peculiarly adapted or insulating purposes and for the formation of insulators for line conductors or high voltage current.

A batch for making the foregoing glass W1ll consist approximately of 69.50% silica, 20% boric acid, 6% cryolite, 4% sodium nitrate and .5% calcium oxide.

Although I have described and disclosed a spec fic composition as illustrative of the invention herein, I do not desire to limit myself to the substitutions may obviously be made in the exact proportions and by way of equivalent materials without departing from thespirit of this invention, as set forth in the appended claims, and in are drawn specifically to the combination of elements set forth including calcium, it should be understood that metals of the cal- 0111111 group, be substituted therefor, all within the scope of the claims.

By the use of the expression .low alkali content in the claims, it is intended that the content shall be 5% or under.

at I claim is:

1. A glass containing silica, boric oxid and an alkali earth, and having a coefficient of expansion not greater than .0000035.

2. glass containing silica, boric oxid,

same, as various changes and although the claims heresuch as'magnesium, etc, may I alumina and an alkali earth, and having a v silica and having a coefliclent of expansion not greater than .0000035,

5. A glass containing boric oxid, alumina, calcium oxid, and a relatively high percentage of silica and having a coeflicient of expansion not greater than .0000035.

6. A glass containing boric oxid, alumina,

calcium oxid, a small amount of an alkali,

and a relatively large percentage of silica, and having acoeflicient of expansion not gr ter than .0000035.

A glass of substantially the followmg analysis: v

and having a v v proximately .0000035, V

8 A glass containing not less than 78% pansion not greater than coefficient of expansion of ap of silica, under 5% of alkali, alumina, an alkali earth, and borio oxide;

9. A lass containing. a high silica content, un er5% of alkali, alumina, an alkali earth, and boric oxide, and having a coefficient of expansion not greater than .0000035.

10. A borosilicate glass containing an alkali earth and not over 5% of alkali.

11. A boro silicate glass containing an allliali earth, alumina and not over 5% of alali.

12. A hero silicate glass containing approximately 78% of silica, alumina an alkali earth, and a low alkali content.

13. A boro silicate glass having a high 15 silica content, and containing alumina, an alkali earth and a low alkali content.

14:. A"boro silicate glass containing approximately 7 8% of silica, alumina, traces of alkali earth, and not over 5% of alkali.

15. A hero silicate glass containing traces of alkali earth, and low in alkali content.

16. A boro silicate glass containing calcium and low in alkali content.

In witness whereof I have hereunto set 25 my hand. this 11th day of September, 1916 FRED M. LOCKE. 

